It seems the role of the rulesone It was changed throughout the history of D&D.
For example, as this answer says, there was an explicit destination between "crunch" and "fluff" in the fourth edition:
a distinction between "ignorable fluff" and the "real rules"
Such separation is a prominent feature of 4e
Apart from this, were there other changes in how the rules were supposed to be interpreted between editions? I am mainly interested in the most popular "modern" editions, so narrowing down the question, How was the role of the rules changed in the fifth edition compared to 3.5e?
one: By "the role of the rules" I mean "how the rules should be used to run a game".